This invention pertains to an orthodontic wedge which is used to effect rotation of a tooth about its own longitudinal axis.
Among the many corrective actions and movements which are used during different orthodontic treatment plans is rotation of a tooth about its own axis. There are a number of instances in which it is desirable to accomplish this kind of action through the use of what is known as a rotational wedge. In general terms, such a device acts between the tooth and a force-effecting arch wire, on one side of the tooth, to create the intended rotation-producing force on the tooth.
As an illustration of a circumstance wherein the use of a wedge is desirable, it is sometimes the case that a bracket which is used to tie in an arch wire to a tooth is not properly located, in an angular sense, relative to the tooth's longitudinal axis, whereby effective rotation cannot be imparted without the use of a wedge. In other words, and during an orthodontic program, it may be discovered that more of a rotational force is required on a tooth than can be achieved without shifting the angular position of the bracket thereon, or using a wedge. Shifting of a bracket is time-consuming and costly, and is usually sought to be avoided.
Another instance where a wedge of the type indicated is extremely helpful is in the case where a tooth's initial orientation in a mouth is considerably rotated in one direction, and requires rather severe correction. Such a tooth often has a tendency, even after the completion of orthodontic treatment, to re-rotate or return toward the angular rotational position which it initially had. To take care of this situation it is often desirable to over-rotate the tooth in the opposite direction, so that when it tends to return, it will tend to return toward a correct angular position. Such over-rotation as a corrective action is most easily accomplished using a rotational wedge.
Further, it is sometimes the case that an orthodontist is not able to tell initially from a tooth's anatomy what should be the proper angular positioning of a bracket relative to the tooth's axis. In other words, he may suspect from the beginning that wherever he places the bracket relative to the tooth's axis, there will come a time when a rotational force is necessary, and the bracket will at that time not be in a proper position. Obviously, a wedge is quite helpful in this situation.
A general object of the present invention, therefore, is to provide a uniquely configured and constructed rotation wedge conveniently usable for all of the above-mentioned purposes, as well as for many others.
Another object of the invention is to provide such a wedge which is simple in construction and easy to install and use.
Still a further object of the invention is to provide a wedge of the type generally indicated which is reliably effective over extended periods of time in a person's mouth.
According to a preferred embodiment of the invention, the wedge is made of a mouth-fluid-resistant elastomeric material, such as a urethane resin material. It includes a thin, generally planar web portion having a pair of openings for releasably fitting over and encircling a pair of conventional orthodontic bracket posts. Joined integrally with the web portion is a thick bulge portion, or enlargement, which extends along one side of the web portion. With the wedge properly fitted in place, the enlargement therein is disposed at an outer set of sides of the posts to which the web portion is attached, and the enlargement acts to deflect an attached arch wire out of the path which it would normally follow through the usual arch wire slot defined in the bracket.
Formed on the outside and outwardly facing surface of the enlargement are two projecting mounds, or projections, which are spaced apart so as to straddle and engage opposite sides of an arch wire. These mounds function to prevent angulation or twisting of the wedge out of a position where the bulge portion can act effectively against the wire.
These and other objects and advantages which are attained by the invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.